Defecography: An Overview of Technique, Interpretation, and Impact on Patient Care

Physiology of lower gastrointestinal tract

BACKGROUND

The lower gastrointestinal (GI) tract, formed from the midgut and hindgut, encompasses the colon, rectum and anal canal.

AIM

The aim of this review is to provide an overview of the anatomy and physiology of the lower GI tract.

METHODS

Literature review on anatomy and physiology of the lower GI tract, including normal motility and phases of defecation. It derives its blood supply from the superior and inferior mesenteric arteries while it is innervated by the extrinsic autonomic (the thoracolumbar and sacral nerves) and the intrinsic enteric nervous system. The colon has four layers: mucosa, submucosa, muscularis externa and serosa. The anal canal ends in the internal and external anal sphincters (EASs) involved in continence and defecation. The lower GI tract is predominantly involved in digestion, absorption, defecation and protection. Defecation is a complex process that requires inter-neural (enteric and autonomic nervous systems), neurohormonal and neuromuscular coordination. It has four phases which include basal, pre-expulsive, expulsive and end phase. High-propagating contractions in the colon propel stool to the rectum leading to rectal distention and the recruitment of the recto-anal inhibitory reflex. Once able, the EAS, under full conscious control, is then relaxed allowing stool to be evacuated. Other defecation reflexes include the gastrocolic, gastroileal and coloanal reflexes.

CONCLUSIONS

Recent advances provide novel techniques to investigate motility patterns including high-resolution manometry protocols with automated assessments, magnetic resonance imaging techniques for defecography, wireless motility capsules and fecobionics.

Defecating proctography: A pictorial essay

OBJECTIVES

To provide an illustrative description of the technique and spectrum of findings in defecating proctography.

KEY FINDINGS

Important findings on defecating proctography include rectocoele, enterocoele, sigmoidocoele, cystocoele, intussusception, rectal prolapse, descending perineum, incomplete emptying, anismus, and faecal incontinence. This review article illustrates these key findings with examples.

CONCLUSION

Defecating proctography is a well-established and cost-effective method of assessing disordered defecation. In conjunction with clinical information and other diagnostic tests, findings on defecating proctography can guide appropriate multidisciplinary management and may lead to improvement in embarrassing and debilitating symptoms in many patients.

IMPLICATIONS FOR PRACTICE

This review article provides a suggested technique and covers the spectrum of findings on defecating proctography.

Value of Defecography in the Diagnostic and Therapeutic Management of the Modified Wells Procedure for Rectal Prolapse

The main aim of this study was to explore the role of defecography in the preoperative diagnosis and postoperative evaluation of rectal prolapse surgery (modified Wells procedure). We collected and summarized the X-ray performance and then analyzed the results of 107 patients with defecatory dysfunction who underwent defecography from January 2020 to March 2021. Furthermore, the preoperative and 6-month postoperative defecography results and clinical symptoms of 25 patients who underwent rectal prolapse surgery (modified Wells procedure) were compared. Results showed that among the 107 patients with defecation dysfunction, women had worse defecography results than men (P < 0.01). A total of 25 patients successfully completed the surgery without complications such as infection and intestinal fistula and there was no recurrence at 12 months of follow-up. Compared with the preoperative results, anorectal angle during defecation, the depth of rectocele, and perineal descent were significantly improved after the surgery (P < 0.01). Moreover, the patient's feeling of obstructed defecation and incomplete defecation was significantly relieved compared to that before the procedure (P < 0.01). In conclusion, defecography can be used to diagnose rectal prolapse preoperatively and evaluate the surgical effect combined with clinical symptoms postoperatively, which provides a clinical reference.

Analysis of Intestinal Movements with Spatiotemporal Maps: Beyond Anatomy and Physiology

Over 150 years ago, methods for quantitative analysis of gastrointestinal motor patterns first appeared. Graphic representations of physiological variables were recorded with the kymograph after the mid-1800s. Changes in force or length of intestinal muscles could be quantified, however most recordings were limited to a single point along the digestive tract.In parallel, photography and cinematography with X-Rays visualised changes in intestinal shape, but were hard to quantify. More recently, the ability to record physiological events at many sites along the gut in combination with computer processing allowed construction of spatiotemporal maps. These included diameter maps (DMaps), constructed from video recordings of intestinal movements and pressure maps (PMaps), constructed using data from high-resolution manometry catheters. Combining different kinds of spatiotemporal maps revealed additional details about gut wall status, including compliance, which relates forces to changes in length. Plotting compliance values along the intestine enabled combined DPMaps to be constructed, which can distinguish active contractions and relaxations from passive changes. From combinations of spatiotemporal maps, it is possible to deduce the role of enteric circuits and pacemaker cells in the generation of complex motor patterns. Development and application of spatiotemporal methods to normal and abnormal motor patterns in animals and humans is ongoing, with further technical improvements arising from their combination with impedance manometry, magnetic resonance imaging, electrophysiology, and ultrasonography.

Chronic Constipation: Gastroenterohepatologist's Approach

BACKGROUND

Constipation is a common problem in gastroenterological practice. The prevalence of constipation is about 16%. Constipation can be primary or secondary.

SUMMARY

The diagnostic and therapeutic approach to patients with constipation begins with a detailed history and physical examination. In selected cases, the use of additional diagnostic procedures is very important. This includes the use of laboratory, endoscopic, and radiological examinations, as well as advanced physiological testing (anorectal manometry, balloon expulsion test, colonic transit studies, and defecography). Constipation therapy can be both nonoperative and operative. Nonoperative therapy includes the application of a lifestyle measures, pharmacotherapy and biofeedback therapy. Key Messages: Two key things when taking a medical history and physical examination are to rule out the existence of alarm symptoms/signs and to rule out secondary constipation (primarily drug-induced). Therapy begins with lifestyle modification, and in case of failure, bulk or osmotic laxatives are used. In case of failure, the use of lubiprostone is indicated, as well as linaclotide. Surgical treatment of constipation is reserved for cases of refractory constipation, with delayed intestinal transit.

Anorectal Physiology Testing for Prolapse-What Tests are Necessary?

Rectal prolapse frequently occurs in conjunction with functional and anatomic abnormalities of the bowel and pelvic floor. Prolapse surgery should have as its goal not only to correct the prolapse, but also to improve function to the greatest extent possible. Careful history-taking and physical exam continue to be the surgeon's best tools to put rectal prolapse in its functional context. Physiologic testing augments this and informs surgical decision-making. Defecography can identify concomitant middle compartment prolapse and pelvic floor hernias, potentially targeting patients for urogynecologic consultation or combined repair. Other tests, including manometry, ultrasound, and electrophysiologic testing, may be of utility in select cases. Here, we provide an overview of available testing options and their individual utility in rectal prolapse.

Barium Defaecating Proctography: Experience from a Tertiary Referral Center

Objective Pelvic floor dysfunction (PFD) is a major health care problem predominately affecting the elderly female. It impairs quality of life and patients increasingly expect a solution. Barium defaecating proctography (BDP) is frequently used in the assessment of patients with PFD. The aim of this study was to present our findings from BDP and to look at the proportion of patients who went on to have surgery following their investigations.

Methods All patients who underwent BDP in a tertiary referral center were identified retrospectively from the computerized radiology information system. Demographic data and radiologic findings were extracted. Data regarding those who had surgery were retrieved from the anonymized patient registry.

Results A total of 671 patients had a BDP during the study period. The main symptoms investigated were obstructed defecation or chronic constipation (64%). Complete barium evacuation was observed in 70% of the patients, while 17% were noted to have incomplete and 13% no evacuation. A large rectocele (>5 cm) was noted in 38% while nearly 5% had frank prolapse. There was no significant association between a rectocele and any of the presenting symptoms. Seventy-eight (12%) patients went on to have operation, of which 17 (22%) had multiple procedures. Three patients ended up with a permanent stoma.

Conclusion BDP contributes to decision making in patients with PFD. However, results need to be interpreted with caution and in conjunction with other tests and clinical examination to maintain a low rate of operation and reduce the risk of adverse outcomes for these patients.

Extraperineal enterocele in male: A case report and literature review

INTRODUCTION

Enterocele is a herniation of the small bowel through the cul-de-sac. It is uncommon and most often seen in elder females. Large enterocele manifesting as rectal prolapse is exceedingly rare and only few cases are reported previously. Due to it rarity, the best surgical treatment is not yet established especially in male patients. We present a case of enterocele causing rectal prolapse in a male patient that was treated surgically.

PRESENTATION OF CASE

A 47-year-old African American male with chronic constipation and straining presented with manually reducible rectal prolapse. A defecography revealed a large enterocele prolapsing through the anterior rectal wall. The patient underwent an open posterior suture rectopexy with peritoneoplasty. His symptoms completely resolved after surgery, and repeat defecography three months after the procedure showed no sign of recurrence.

DISCUSSION & CONCLUSION

Extraperineal enterocele in male is a rare disease. Rectopexy with peritoneoplasty can provide a great symptom relieve and improvement on defecography. Long-term outcome should be evaluated.

High Prevalence of Slow Transit Constipation in Patients With Gastroparesis

Background/Aims

Current evidence suggests the presence of motility or functional abnormalities in one area of the gastrointestinal tract increases the likelihood of abnormalities in others. However, the relationship of gastroparesis to chronic constipation (slow transit constipation and dyssynergic defecation) has been incompletely evaluated.

Methods

We retrospectively reviewed the records of all patients with chronic dyspeptic symptoms and constipation who underwent both a solid gastric emptying scintigraphy and a high-resolution anorectal manometry at our institution since January 2012. When available, X-ray defecography and radiopaque marker colonic transit studies were also reviewed. Based on the gastric emptying results, patients were classified as gastroparesis or dyspepsia with normal gastric emptying (control group). Differences in anorectal and colonic findings were then compared between groups.

Results

Two hundred and six patients met the inclusion criteria. Patients with gastroparesis had higher prevalence of slow transit constipation by radiopaque marker study compared to those with normal emptying (64.7% vs 28.1%, P = 0.013). Additionally, patients with gastroparesis had higher rates of rectocele (88.9% vs 60.0%, P = 0.008) and intussusception (44.4% vs 12.0%, P = 0.001) compared to patients with normal emptying. There was no difference in the rate of dyssynergic defecation between those with gastroparesis vs normal emptying (41.1% vs 42.1%, P = 0.880), and no differences in anorectal manometry findings.

Conclusions

Patients with gastroparesis had a higher rate of slow transit constipation, but equal rates of dyssynergic defecation compared to patients with normal gastric emptying. These findings argue for investigation of possible delayed colonic transit in patients with gastroparesis and vice versa.